int
backtrace_full (struct backtrace_state *state, int skip,
backtrace_full_callback callback,
backtrace_error_callback error_callback, void *data)
{
struct backtrace_data bdata;
void *p;
bdata.skip = skip + 1;
bdata.state = state;
bdata.callback = callback;
bdata.error_callback = error_callback;
bdata.data = data;
bdata.ret = 0;
/* If we can't allocate any memory at all, don't try to produce
file/line information. */
p = backtrace_alloc (state, 4096, NULL, NULL);
if (p == NULL)
bdata.can_alloc = 0;
else
{
backtrace_free (state, p, 4096, NULL, NULL);
bdata.can_alloc = 1;
}
_Unwind_Backtrace (unwind, &bdata);
return bdata.ret;
}
void
backtrace_release_view (struct backtrace_state *state,
struct backtrace_view *view,
backtrace_error_callback error_callback,
void *data)
{
backtrace_free (state, view->base, view->len, error_callback, data);
view->data = NULL;
view->base = NULL;
}
void *
backtrace_alloc (struct backtrace_state *state,
size_t size, backtrace_error_callback error_callback,
void *data)
{
void *ret;
int locked;
struct backtrace_freelist_struct **pp;
size_t pagesize;
size_t asksize;
void *page;
ret = NULL;
/* If we can acquire the lock, then see if there is space on the
free list. If we can't acquire the lock, drop straight into
using mmap. __sync_lock_test_and_set returns the old state of
the lock, so we have acquired it if it returns 0. */
if (!state->threaded)
locked = 1;
else
locked = __sync_lock_test_and_set (&state->lock_alloc, 1) == 0;
if (locked)
{
for (pp = &state->freelist; *pp != NULL; pp = &(*pp)->next)
{
if ((*pp)->size >= size)
{
struct backtrace_freelist_struct *p;
p = *pp;
*pp = p->next;
/* Round for alignment; we assume that no type we care about
is more than 8 bytes. */
size = (size + 7) & ~ (size_t) 7;
if (size < p->size)
backtrace_free_locked (state, (char *) p + size,
p->size - size);
ret = (void *) p;
break;
}
}
if (state->threaded)
__sync_lock_release (&state->lock_alloc);
}
if (ret == NULL)
{
/* Allocate a new page. */
pagesize = getpagesize ();
asksize = (size + pagesize - 1) & ~ (pagesize - 1);
page = mmap (NULL, asksize, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (page == NULL)
error_callback (data, "mmap", errno);
else
{
size = (size + 7) & ~ (size_t) 7;
if (size < asksize)
backtrace_free (state, (char *) page + size, asksize - size,
error_callback, data);
ret = page;
}
}
return ret;
}